diff --git a/src/core/set_addition.pm6 b/src/core/set_addition.pm6
index e9080477df3..2b849537b4d 100644
--- a/src/core/set_addition.pm6
+++ b/src/core/set_addition.pm6
@@ -144,7 +144,7 @@ multi sub infix:<(+)>(Any $, Failure:D $b) { $b.throw }
 multi sub infix:<(+)>(Failure:D $a, Any $) { $a.throw }
 multi sub infix:<(+)>(Any $a, Any $b) {
     nqp::if(
-      nqp::istype($a,QuantHash),
+      nqp::istype($a,QuantHash) && nqp::isconcrete($a),
       nqp::if(
         nqp::istype($a,Mixy) || nqp::istype($b,Mixy),
         infix:<(+)>($a.Mixy,  $b.Mix(:view)),
diff --git a/src/core/set_intersection.pm6 b/src/core/set_intersection.pm6
index a82064efbad..f4a3154e464 100644
--- a/src/core/set_intersection.pm6
+++ b/src/core/set_intersection.pm6
@@ -130,7 +130,10 @@ multi sub infix:<(&)>(Failure:D $a, Any $) { $a.throw }
 # Note that we cannot create a Setty:D,Any candidate because that will result
 # in an ambiguous dispatch, so we need to hack a check for Setty in here.
 multi sub infix:<(&)>(Any $a, Any $b) {
-    infix:<(&)>(nqp::istype($a,Setty) ?? $a !! $a.Set,$b.Set)
+    infix:<(&)>(
+      nqp::istype($a,Setty) && nqp::isconcrete($a) ?? $a !! $a.Set,
+      $b.Set
+    )
 }
 
 multi sub infix:<(&)>(**@p) {
diff --git a/src/core/set_multiply.pm6 b/src/core/set_multiply.pm6
index b5b5d8137f4..9ab84737991 100644
--- a/src/core/set_multiply.pm6
+++ b/src/core/set_multiply.pm6
@@ -54,9 +54,11 @@ multi sub infix:<(.)>(Failure:D $a, Any $) { $a.throw }
 # in here.
 multi sub infix:<(.)>(Any $a, Any $b) {
     infix:<(.)>(
-      nqp::istype($a,Setty)
-        ?? $a.Baggy
-        !!  nqp::istype($a,Baggy) ?? $a !! $a.Bag,
+      nqp::isconcrete($a)
+        ?? nqp::istype($a,Setty)
+          ?? $a.Baggy
+          !! nqp::istype($a,Baggy) ?? $a !! $a.Bag
+        !! $a.Bag,
       $b.Bag
     )
 }
diff --git a/src/core/set_union.pm6 b/src/core/set_union.pm6
index 93d7fe2a0af..4ef8271edbd 100644
--- a/src/core/set_union.pm6
+++ b/src/core/set_union.pm6
@@ -154,25 +154,33 @@ multi sub infix:<(|)>(Failure:D $a, Any $b) { $a.throw }
 multi sub infix:<(|)>(Any $a, Failure:D $b) { $b.throw }
 multi sub infix:<(|)>(Any $a, Any $b) {
     nqp::if(
-      nqp::istype($a,Mixy),
-      infix:<(|)>($a, $b.Mix),
+      nqp::isconcrete($a),
       nqp::if(
-        nqp::istype($a,Baggy),
-        infix:<(|)>($a, $b.Bag),
+        nqp::istype($a,Mixy),
+        infix:<(|)>($a, $b.Mix),
         nqp::if(
-          nqp::istype($a,Setty),
-          infix:<(|)>($a, $b.Set),
+          nqp::istype($a,Baggy),
+          infix:<(|)>($a, $b.Bag),
           nqp::if(
-            nqp::istype($b,Mixy),
-            infix:<(|)>($a.Mix, $b),
+            nqp::istype($a,Setty),
+            infix:<(|)>($a, $b.Set),
             nqp::if(
-              nqp::istype($b,Baggy),
-              infix:<(|)>($a.Bag, $b),
-              infix:<(|)>($a.Set, $b.Set)
+              nqp::isconcrete($b),
+              nqp::if(
+                nqp::istype($b,Mixy),
+                infix:<(|)>($a.Mix, $b),
+                nqp::if(
+                  nqp::istype($b,Baggy),
+                  infix:<(|)>($a.Bag, $b),
+                  infix:<(|)>($a.Set, $b.Set)
+                )
+              ),
+              infix:<(|)>($a, $b.Set)
             )
           )
         )
-      )
+      ),
+      infix:<(|)>($a.Set, $b)
     )
 }